CARDURA XL

CARDURA XL contains doxazosin which is a quinazoline compound with the chemical name 1-(4-amino-6,7-dimethoxy-2-quinazolinyl)-4-(1,4-benzodioxan-2-ylcarbonyl) piperazine methanesulfonate. The empirical formula for doxazosin mesylate is C 23 H 25 N 5 O 5 • CH 4 O 3 S and the molecular weight is 547.6. It has the following structure: CARDURA XL is an extended-release tablet for oral use and is designed to deliver 4 or 8 mg of doxazosin as the free base. Each 4 and 8 mg tablet contains 5.1 and 10.2 mg doxazosin mesylate (includes a 5% overage) to ensure the labeled dose of 4 and 8 mg doxazosin as the free base (equivalent to 4.9 and 9.8 mg of doxazosin mesylate), is delivered. The inactive ingredients for CARDURA XL are black iron oxide, cellulose acetate, hypromellose, Macrogol ® , magnesium stearate, pharmaceutical glaze, polyethylene oxide, red ferric oxide, sodium chloride and titanium dioxide. CARDURA XL System Components and Performance CARDURA XL is similar in appearance to a conventional tablet. It consists, however, of an osmotically active drug core surrounded by a semipermeable membrane. The core itself is divided into two layers: an “active” layer containing the drug, and a “push” layer containing pharmacologically inert (but osmotically active) components. The membrane surrounding the tablet is permeable to water, but not to drug or osmotic excipients. As water from the gastrointestinal tract enters the tablet, pressure increases in the osmotic layer and “pushes” against the drug layer, resulting in the release of drug through a small, laser-drilled orifice in the membrane on the drug side of the tablet. CARDURA XL utilizes GITS (Gastrointestinal Therapeutic System) which is designed to provide a controlled rate of delivery of doxazosin into the gastrointestinal lumen which is independent of pH or gastrointestinal (GI) motility. The function of CARDURA XL depends upon the existence of an osmotic gradient between the contents of the bi-layer core and fluid in the GI tract. Drug delivery is essentially constant as long as the osmotic gradient remains constant, and then gradually falls to zero. The biologically inert components of the tablet remain intact during GI transit and are eliminated in the feces as an insoluble shell. Doxazosin Mesylate Structural Formula

CARDURA ® XL is indicated for the treatment of the signs and symptoms of benign prostatic hyperplasia (BPH). CARDURA XL is not indicated for the treatment of hypertension. CARDURA XL is an alpha 1 adrenergic antagonist indicated for the treatment of the signs and symptoms of benign prostatic hyperplasia. ( 1 ) CARDURA XL is not indicated for the treatment of hypertension. ( 1 )

Recommended starting dose (initial therapy or switching from immediate-release): 4 mg once daily with breakfast ( 2.1 , 2.2 ) Dose range: 4 to 8 mg once daily ( 2.1 ) 2.1 General Dosing Information The initial dose of CARDURA XL, 4 mg given once daily, should be administered with breakfast. Depending on the patient’s symptomatic response and tolerability, the dose may be increased to 8 mg, the maximum recommended dose. The recommended titration interval is 3-4 weeks. If CARDURA XL administration is discontinued for several days, therapy should be restarted using the 4 mg once daily dose. Tablets should be swallowed whole, and must not be chewed, divided, cut, or crushed. 2.2 Patients Switching from CARDURA to CARDURA XL If switching from CARDURA immediate-release (IR) to CARDURA XL, therapy should be initiated with the lowest dose (4 mg once daily). Prior to starting therapy with CARDURA XL, the final evening dose of CARDURA should not be taken. 2.3 Concomitant Administration with PDE-5 Inhibitors Concomitant administration of CARDURA XL with a PDE-5 inhibitor can result in additive blood pressure lowering effects and symptomatic hypotension; therefore, PDE-5 inhibitor therapy should be initiated at the lowest dose in patients taking CARDURA XL.

CARDURA XL is contraindicated in patients with a known hypersensitivity to doxazosin, other quinazolines (e.g., prazosin, terazosin), or any of the inert ingredients. Allergic reactions to doxazosin and other quinazolines have included skin rash, urticaria, pruritus, angioedema, and respiratory symptoms [see Adverse Reactions (6.2) ] . Patients with known sensitivity to doxazosin, other quinazolines, or any of the inert ingredients ( 4 )

The most commonly reported adverse reactions from clinical trials are asthenia, headache, hypotension, and dizziness. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Viatris at 1-877-446-3679 (1-877-4-INFO-RX) or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in clinical practice. The incidence of adverse reactions was derived from two controlled efficacy and safety trials involving 1473 BPH patients. In Study 1, CARDURA XL (n = 317) was compared to doxazosin IR tablets (n = 322) and to placebo (n = 156). In Study 2, CARDURA XL (n = 350) was compared just to doxazosin IR tablets (n = 330). In both of these studies, CARDURA XL was initiated at a dose of 4 mg, which could be increased by the investigator to 8 mg after seven weeks if an adequate response was not seen [see Clinical Studies (14.1) ] . Similarly, doxazosin IR was begun at a dose of 1 mg, which was increased in all patients to 2 mg after 1 week, followed by the option to increase to 4 mg after 4 weeks, and 8 mg after 7 weeks. The most commonly reported adverse reactions leading to discontinuation in the CARDURA XL group were dizziness, dyspnea, asthenia, headache, hypotension, postural hypotension, and somnolence. The rates of discontinuation for adverse reactions were 6%, 7% and 3% in the CARDURA XL, doxazosin IR, and placebo groups, respectively. Table 1 lists the incidence rates of adverse reactions derived from all reported adverse events in the two controlled studies (Studies 1 and 2) combined, at a rate greater than placebo and in 1% or more of patients treated with CARDURA XL. TABLE 1 Adverse Reactions, Derived from All Adverse Events Exceeding Placebo Rate and Occurring in ≥ 1% of BPH Patients Treated with CARDURA XL Body System CARDURA XL (N = 666) Doxazosin IR (N = 651) Placebo (N = 156) BODY AS A WHOLE Abdominal Pain 1.8% 2.3% 0.6% Asthenia 3.9% 6.9% 1.3% Headache 6.0% 5.1% 4.5% CARDIOVASCULAR Hypotension 1.7% 1.8% 0.0% Postural Hypotension 1.2% 2.2% 0.6% DIGESTIVE Dyspepsia 1.4% 1.2% 0.0% Nausea 1.2% 2.3% 0.6% MUSCULOSKELETAL Myalgia 1.4% 0.5% 0.0% NERVOUS Dizziness 5.3% 9.1% 1.9% Somnolence 1.5% 1.2% 0.0% Vertigo 1.5% 4.1% 0.6% RESPIRATORY Dyspnea 1.2% 1.2% 0.0% Respiratory Tract Infection 4.8% 4.5% 1.9% UROGENITAL Urinary Tract Infection 1.4% 0.8% 0.6% Additional adverse events reported with CARDURA XL, reported by less than 1% of patients, and those of clinical interest include: Cardiovascular System: angina pectoris, syncope, tachycardia, chest pain, palpitations; Digestive System: diarrhea; Musculoskeletal System: arthralgia; Nervous System: libido decreased; Urogenital System: impotence, dysuria. In general, the adverse events reported in the open-label safety extension, in approximately 295 BPH patients treated for up to 37 weeks, were similar in type and frequency to the events described above in the controlled trials. 6.2 Postmarketing Experience The following adverse events have been identified during post-approval use of doxazosin. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure. Autonomic Nervous System: priapism; Cardiovascular System: cerebrovascular accidents, dizziness postural, myocardial infarction; Central and Peripheral Nervous System: hypoesthesia, paresthesia; Endocrine System: gynecomastia; Gastrointestinal System: gastrointestinal obstruction, vomiting; General Body System: fatigue, hot flushes, malaise; Heart Rate/Rhythm: bradycardia, cardiac arrhythmias; Hematopoietic: leukopenia, purpura, thrombocytopenia; Liver/Biliary System: abnormal liver function tests, hepatitis, hepatitis cholestatic, jaundice; Musculoskeletal System: muscle cramps, muscle weakness; Psychiatric: agitation, anorexia, nervousness; Respiratory System: bronchospasm aggravated; Skin Disorders: alopecia, urticaria, skin rash, pruritus; Special Senses: blurred vision, Intraoperative Floppy Iris Syndrome [see Warnings and Precautions (5.2) ] ; Urinary System: hematuria, micturition disorder, micturition frequency, nocturia, polyuria. There have been rare reports of gastrointestinal irritation and gastrointestinal bleeding with use of another drug in this non-deformable sustained release formulation, although causal relationship to the drug is uncertain.

Caution should be exercised when concomitantly administering CARDURA XL with a strong cytochrome P450 (CYP) 3A4 inhibitor. ( 7.1 ) Concomitant administration of CARDURA XL with a phosphodiesterase-5 (PDE-5) inhibitor can result in additive blood pressure lowering effects and symptomatic hypotension. ( 7.3 ) 7.1 CYP 3A4 Inhibitors No in vivo drug interaction studies were conducted with CARDURA XL. In vitro studies suggest that doxazosin is a substrate of CYP 3A4. Caution should be exercised when concomitantly administering CARDURA XL with a strong CYP 3A4 inhibitor, such as atazanavir, clarithromycin, indinavir, itraconazole, ketoconazole, nefazodone, nelfinavir, ritonavir, saquinavir, telithromycin, or voriconazole [see Clinical Pharmacology (12.3) ] . 7.2 Antihypertensive Medications Pharmacodynamic interactions between CARDURA XL and antihypertensive medications or other vasodilating agents have not been determined. 7.3 PDE-5 Inhibitors Concomitant administration of CARDURA XL with a PDE-5 inhibitor can result in additive blood pressure lowering effects and symptomatic hypotension [see Dosage and Administration (2.3) ] .